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Helping a buddy finish his 2011 JK Dana 30HP reassembly, a previous guy bailed on him after taking it apart and destroying the original gears (it was all froze up from water in the axle)
NOTE: I have only done a few gear setups.
He got a used stock ring & pinion gear with low miles and a Motive install kit.
Right now we have just one carrier shim in place, a .006 on the opposite side of the ring gear, Originally he got the carrier back with no shims / new bearings installed and we had no backlash (fairly tight fit), we tried using a .010 shim opposite gear and it was a bear to get in and even worse to remove (had to use a ratchet strap from carrier to frame making it real tight and then use a pry bar & hammer - pry bar alone without strap would not remove it - I thought I was going to need a case spreader)
Without using the crush sleeve yet but with the right pinion preload, and with a .04 backlash (should be .05-.08)
So with a .006 shim on the opposite side of the gear alone we got the following patterns;
I think if the top one is the coast, and the bottom one drive I might be OK according to the chart I found below
Carrier shim determination requires precise measurement of the carrier movement without a pinion installed then again with the pinion installed. That is the only way to properly determine the shim thickness and set the bearing preload.
Also another question is on the Crush Sleeve and Preload, even when we had no shims behind the carrier bearings at all the carrier has a fair amount of preload.
So when adjust the Pinion Preload with the Crush sleeve, at 12-15" is the carrier in place, or carrier removed from axle?
Carrier shim determination requires precise measurement of the carrier movement without a pinion installed then again with the pinion installed. That is the only way to properly determine the shim thickness and set the bearing preload.
Carrier in all cases had to be hammered in with a a dead blow (even without any shims)
What is really strange to me is the are two big washers (size of the race), one each between the races and axle tubes - these washers are like a 1/16" thick heavy duty washers, I never seen this on the TJ/XJ axles I set up... is this norm on a JK Dana 30?
Carrier in all cases had to be hammered in with a a dead blow (even without any shims)
What is really strange to me is the are two big washers (size of the race), one each between the races and axle tubes - these washers are like a 1/16" thick heavy duty washers, I never seen this on the TJ/XJ axles I set up... is this norm on a JK Dana 30?
Does this diff use a crush sleeve? I didn't think it did. While you're setting it up, you just tighten the pinion nut until the pinion bearing preload is right. THEN install the carrier setting the backlash with carrier shims THEN checking the pattern. Next, disassemble and adjust the pinion shim to fix the patter and repeat. Once you get all the shims set so that the backlash AND pinion depth are good, THEN you tear it all down and install the crush sleeve or shim the pinion bearings to get the preload (depending on which diff) and reassemble for the final time.
The questions you ask make me worry about your diff build. Don't use it until you're sure you did it right.
The differential was disassembled with a crush sleeve in it, and the "Shims" behind the carrier races were so over 1/16" thick, you could not bend them with a pair of plyers, not like anything I have seen in an XJ/TJ Dana 30 or 44 carrier. Its assembled with a good pattern and working fine now.
10-05-2015, 01:19 PM
Gear Pattern Opinions
